Top drive assembly

ABSTRACT

A top drive assembly for wellsite operations may include a quill, a swivel including a swivel housing and a swivel bearing therein in which the quill is supported, a drive system for applying torque to the quill, and link arm hangers extending from the swivel housing and formed to accept and retain link arms.

FIELD

The present invention is directed to a top drive assembly and a swiveltherefor.

BACKGROUND

A top drive assembly is used in oilfield operations for manipulating awellbore string such as a drill string or a casing or liner string. Thetop drive assembly is supported in a rig such as a mast or derrick forsupporting and axially and rotationally driving the wellbore string.

Referring to FIG. 1, an example of a prior art top drive assembly isshown. The top drive assembly 10 may be supported from a hook in a rig(not shown) by use of a hoisting apparatus 12 such as a bail, links,blocks, etc., and may be stabilized by connection to a torque track 14.A top drive assembly generally may include a quill 16 that extends fromthe top drive assembly downwardly for connection directly, or indirectlyas through a clamp 18 etc., to the wellbore string 20, a swivel 22including a swivel bearing for rotationally supporting the quill, atorque and drive system 24 that may include, for example, a gear box 26and motor 28 for applying torque to the quill, and link arms 30 withelevators 34 connected via link hangers 31 on a collar 32 and load nut33 to the quill for supporting the weight of the wellbore string whenthe wellbore string is supported by the top drive assembly throughelevators 34 but not connected to the quill.

In a typical configuration, as shown, swivel 22 is positioned adjacentthe upper end of the top drive assembly with bail 12 connected to theswivel housing. Quill 16 is supported in the swivel and extends downthrough drive system 24 to extend out at the bottom of assembly 10. Atypical top drive assembly may accommodate a space of about 20 ft (6 m)or more above from the top of the bail to the top of the link armelevators.

In operations employing a top drive assembly; a load path is thereforeset up from the wellbore string through the quill to the swivel and thento the bail through which the load is conveyed to the rig hoistingequipment. When the wellbore string is supported on the elevators, theload path extends through elevators 34 and link arms 30 to the loadcollar and the load nut and then up through the quill to swivel 22 andbail 12. A typical top drive assembly, therefore, effectively forms asingle load path from top to bottom, which is through the quill.

Although the top drive assembly is an integral part of modern wellsiteoperations, the typical top drive configuration has presented problemswith size and reliance on the quill in the load path.

SUMMARY

In accordance with one aspect of the present invention, there isprovided a top drive assembly for wellsite operations, the top driveassembly comprising: a quill; a swivel including a swivel housing and aswivel bearing therein in which the quill is supported; a drive systemfor applying torque to the quill; and link arm hangers extending fromthe swivel housing and formed to accept and retain link arms.

A top drive assembly comprising: a quill; a swivel including a swivelhousing and a swivel bearing therein for supporting the quill; and linkarm hangers connected for load transfer to the swivel housing, the topdrive assembly defining a first load path through the quill and theswivel and a second load path directly from the link hangers to theswivel.

A top drive assembly swivel comprising: a swivel housing and a swivelbearing therein, the swivel housing including a connector for acceptingconnection to a bail and link hangers extending therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood by reference to the drawings ofprior art and possible embodiments, wherein:

FIG. 1 is a side elevation of a prior art top drive assembly;

FIG. 2 is a side elevation of one embodiment of a top drive assemblyaccording to the present invention;

FIG. 3 is a front elevation of the top drive assembly of FIG. 2 with aportion of the swivel shown in section.

FIG. 4 is a side elevation of another embodiment of a top driveassembly; and

FIG. 5 is a section of the swivel and quill of FIG. 4 along lines V-V ofFIG. 4.

DESCRIPTION OF VARIOUS EMBODIMENTS

A top drive assembly 50 is described herein that may be more compact andless complex that many previous top drive assemblies. The top driveassembly described herein offers a dual load path between a rig in whichthe assembly is mounted and a wellbore string 20 to be handled by thetop drive assembly.

Top drive assembly 50 may be supported from a hook in a rig (not shown)by use of a hoisting apparatus such as links 52, a bail, etc. and may bestabilized by a bracket (not shown) for connection to a torque track.

Top drive assembly 50 includes a quill 56, a swivel 72 and link hangers80. For operation to manipulate a wellbore string further parts such asa grabber, link arms 82 and a torque and drive system 94 may be providedand installed.

Quill 56 extends from the top drive assembly downwardly for connectiondirectly or indirectly to the wellbore string 20. For example, in theillustrated embodiment, the quill has connected thereto a sub string 21,which in turn connects directly or indirectly to the wellbore string. Ofcourse, other configurations may be possible such as, for example,including casing clamps, actuators, valves, etc. Wellbore string 20 maybe one or more joints of pipe such as, for example, any of drill pipe,drill collar, casing or a wellbore liner.

Top drive assembly 50 further includes a swivel 72, including a housing73 containing a swivel bearing 74 for supporting quill 56 in a mannerpermitting rotation therein. The swivel also provides connectiondirectly or indirectly to links 52. For example, in the illustratedembodiment, swivel housing 73 has formed thereon devises 75 foraccepting pins 76 connecting between the links and the swivel. Ofcourse, other connection arrangements are possible between the top drivehoisting apparatus and the swivel. However, any such connection shouldbe selected with consideration as to the load that must be accommodatedtherethrough.

Top drive assembly 50 also includes link hangers 80 for accepting andretaining link arms 82 and, therethrough, elevators 84. Link hangers 80form support areas for the link arms. In the illustrated embodiment, thelink hangers are hooked extensions over which the eyes 83 of link arms82 may be hooked. As will be appreciated, a pair of link hangers 80 isusually employed and the link hangers are usually diametricallypositioned so that the link arms hang down on either side of the topdrive.

The swivel 72 and link hangers 80 configuration provide that the linkhangers 80 extend from swivel housing 73 rather than from a connectionto the quill. Link hangers 71 can be formed or mounted in various waysto extend from the swivel housing. For example, the link hangers can beformed integral with the swivel housing, as shown. Alternately, the linkhangers can be connected to the swivel housing by way of welding, boltsor other fasteners, connectors, interlocking arrangements, bearings,etc. Any connection arrangement between the link hangers and the swivelhousing, however, must be selected with consideration as to the loadthat must be accommodated therethrough.

During certain operations using the top drive assembly, the weight ofthe wellbore string will be taken up by the elevators and the link armsand during certain other operations, the weight of the wellbore stringwill be taken up by the quill. In the present top drive assembly, whenthe load is taken up by the link arms, such load is transferred throughthe link arms and the link hangers to the swivel housing and then to thebail. As such, the top drive assembly offers a dual load path includinga first load path through quill 56 and swivel 72 into the bail and asecond load path through link arms 82, link hangers 80 and swivel 72into the bail. In this assembly, therefore, the weight can be carried bythe link arms and the quill may be free for other operations, which may,for example, include rotation of the quill.

Top drive assembly 50, for operation, also includes a torque and drivesystem 94 for applying torque to the quill. In the illustratedembodiment, for example, the torque and drive system includes a gear box96 in a concentric or eccentric configuration and any of various typesof motors 98. Torque and drive system 94 may be positioned in variouslocations on the top drive assembly, for example above or below theswivel, to drive the quill. In the illustrated embodiment, torque anddrive system 94 is positioned above swivel 72. As such, the torque anddrive system is out of the way so that the quill and the link arms donot have to be formed to accommodate the system 94. In particular, thispermits the quill and the link arms to be shorter than in a top driveassembly where the torque and drive system is positioned below theswivel. For example, in one embodiment a top drive assembly similar tothat of FIG. 2 may accommodate a reduced space between the top of thelinks and the bottom of the quill, when compared to a top drive as shownin FIG. 1.

In addition, the torque and drive system, in its position above swivel,is out of the load path and need not, if desired, accommodate astructure in the load path passing therethrough.

Torque and drive system 94 may be connected permanently or detachablyinto the top drive assembly. For example, in the illustrated embodiment,the gearbox of the system is detachably connected to a support surface97 on swivel 72 via a connector 99 and bolts 100. This detachableconnection permits the torque and drive system to be removed from thetop drive assembly for repair or replacement, for example, for selectionto meet desired operational parameters. In one embodiment, the driveassembly connects to the quill via a spline or another drive interface.

In one embodiment, torque and drive system 94 and swivel 72 may have aseparate lubricant/oil storage and supply and may each be sealedindependently of the other such that they can be readily separatedwithout consideration as to leakage or containment of oil/lubricant.

Referring to FIGS. 4 and 5, another top drive assembly 50 a and swivel72 a are shown. Top drive assembly 50 a includes a quill 56 a, a swivel72 a, link hangers 80 a, a pipe grabber assembly 85, link arms 82 and atorque and drive system 94 a.

As in previous embodiments, quill 56 a extends through the swivel andextends downwardly out from the swivel for connection directly orindirectly to a wellbore string. Swivel 72 a includes a housing 73 acontaining a swivel bearing 74 a for supporting quill 56 a andpermitting its rotation about axis x_(R). The swivel also providesconnections 75 a for directly or indirectly securing to hoistingapparatus such as links and block 52 a.

Link hangers 80 a are formed from housing 73 a integral with thematerial of housing, as by molding or machining. As noted hereinbefore,link hangers 80 a support link arms 82. Link hangers 80 a form supportareas for the link arms. In the illustrated embodiment, the link hangersare defined by pockets formed in the swivel housing to accommodate theeyes 83 of the link arms 82 and supports 86 over which the eyes may behooked. Supports 86 define a saddle-shaped upper surface including aconcave curvature over their long axis x_(L), which is that axissubstantially radial to the rotational axis of the top drive assembly,and a convex curvature over an axis perpendicular to axis x_(L). Such asurface curvature forms a saddle-shaped support surface thatsubstantially envelopes the load transfer surface of an eye 83 toenhance contact, and thereby load transfer, therebetween. Apertures 87are formed to accept fasteners for securing a stay plate (not shown)over the pockets to maintain the eyes in the pockets.

Top drive assembly 50 a also includes a torque and drive system 94 a forapplying torque to the quill. In the illustrated embodiment, forexample, the torque and drive system includes a gear box 96 a and amotor 98 a, each of which may be selected from various configurationsand types. In the illustrated embodiment, torque and drive system 94 ais positioned above swivel 72 a. Torque and drive system 94 a may beconnected permanently or detachably into the top drive assembly. Forexample, in the illustrated embodiment, the torque and drive system 94 ais detachably connected to a support surface 97 a on swivel 72 a and thegears of the gearbox are connected to the quill by a releasable splineinterface 107. Support surface 97 a includes holes 109 for retainingbolts (not shown) to connect the torque and drive system. Thisdetachable connection permits the torque and drive system to be removedfrom the top drive assembly for repair or replacement. Seals 110 may beprovided to contain the swivel's lubricant supply.

The swivel housing may be formed to accommodate other modularcomponents. For example, in the illustrated embodiment, the swivelhousing defines a back interface surface 112 including fastener holesonto which a torque track or other component may be connected. Theillustrated swivel further includes a front interface surface 114including fastener holes for retaining grabber assembly 85 or anothercomponent. Swivel 72 a may also include interface apertures 116 forpermitting a pull down connection. As such, the swivel may be modularsuch that any of various parts, including for example, any or all ofsystem 94 a, grabber assembly 85, a torque track or pull down apertures116, can be selected and connected to swivel housing 73, as desired.

Suitable materials and construction for a top drive assembly andcomponents would be apparent to a skilled workman.

While various embodiments have been described in detail, theseembodiments are described to facilitate understanding and are notintended to be used to limit the invention. It is to be understood thata substitutions would be apparent to a skilled workman and suchsubstitutions are to be encompassed by the appended claims.

1. A top drive assembly for wellsite operations, the top drive assemblycomprising: a quill; a swivel including a swivel housing and a swivelbearing therein in which the quill is supported; a drive system forapplying torque to the quill; and link arm hangers extending from theswivel housing and formed to accept and retain link arms.
 2. The topdrive assembly of claim 1 wherein the link arm hangers are formedintegral with the swivel housing.
 3. The top drive assembly of claim 1,the drive system being positioned above the swivel.
 4. The top driveassembly of claim 1 wherein the drive system is detachably connected tothe swivel.
 5. The top drive assembly of claim 1 further comprising agrabber assembly detachably connected to the swivel.
 6. A top driveassembly comprising: a quill; a swivel including a swivel housing and aswivel bearing therein for supporting the quill; and link arm hangersconnected for load transfer to the swivel housing, the top driveassembly defining a first load path through the quill and the swivel anda second load path directly from the link hangers to the swivel.
 7. Thetop drive assembly of claim 6 further comprising a link arm connected oneach link hanger and the second load path extends from link arms to thelink arm hangers.
 8. The top drive assembly of claim 6 wherein the drivesystem is operable to drive the quill with a load passing through thefirst load path.
 9. The top drive assembly of claim 6 wherein the drivesystem is operable to drive the quill while a load passes through thesecond load path.
 10. The top drive assembly of claim 6 furthercomprising a connection on the swivel housing to a top drive hoistingapparatus.
 11. A top drive assembly for wellsite operations, the topdrive assembly comprising: a quill; a swivel including a swivel housingand a swivel bearing therein in which the quill is supported; a drivesystem for applying torque to the quill; and a drive system supportsurface on the swivel housing and formed to detachably connect the drivesystem.
 12. The top drive assembly of claim 11 wherein the swivel andthe drive system each include separate lubricant supplies.
 13. The topdrive assembly of claim 11 wherein the swivel and the drive system eachare separately sealed.
 14. The top drive assembly of claim 11 whereinthe quill and drive system are releasably connected by a splineinterface.
 15. The top drive assembly of claim 11 further comprising afront interface surface on the swivel housing for detachably connectinga grabber assembly.
 16. The top drive assembly of claim 11 furthercomprising a rear interface surface on the swivel for detachableconnection of a torque track.
 17. The top drive assembly of claim 11further comprising a pull down interface formed on the swivel housing.18. The top drive assembly of claim 11 further comprising a pair of linkhangers formed integral with the swivel housing.
 19. A top driveassembly swivel comprising: a swivel housing and a swivel bearingtherein, the swivel housing including a connector for acceptingconnection to a string hoisting apparatus and a pair of link arm hangersextending therefrom.
 20. The top drive assembly swivel of claim 19further comprising a drive system support surface positioned on top ofthe swivel housing.
 21. The top drive assembly swivel of claim 20wherein the drive system support surface includes bolt holes fordetachably connecting the drive system.
 22. The top drive assemblyswivel of claim 19 further comprising a front interface surface on theswivel housing for detachably connecting a grabber assembly.
 23. The topdrive assembly swivel of claim 19 further comprising a rear interfacesurface on the swivel for detachable connection of a torque track. 24.The top drive assembly swivel of claim 19 further comprising a pull downinterface formed on the swivel housing.
 25. The top drive assemblyswivel of claim 19 further comprising a pair of link hangers formedintegral with the swivel housing.
 26. The top drive assembly swivel ofclaim 19 further comprising a link arm hanger thereon, the link armhanger including a saddle-shaped support surface including a convexcurvature over its long axis and a convex curvature over an axisperpendicular to the long axis.